The present invention relates to knife sharpening apparatus, and more particularly to such apparatus which is selectively adjustable to accommodate knives having various blade widths and thicknesses.
Knife sharpening devices designed to maintain a knife blade at a preselected angle relative to a sharpening stone are known in the prior art. Such devices generally include a platform for supporting the stone and a guide bar selectively shiftable with respect to the stone to produce a preselected spacing therebetween. The knife blade, when inserted between the stone and the bar, is maintained at a fixed angle during sharpening.
In prior art knife-sharpening apparatus of the type just described, the relative spacing between the bar and the stone is calibrated according to the spacing between the bar and the platform supporting the stone. Such calibration assumes that the stone is of a fixed, constant thickness. In the case where a sharpening stone having a different thickness is used, or where the upper surface of the stone has been worn down, there is no way accurately to set the spacing between the bar and the stone, short of physically measuring such spacing and adjusting the bar accordingly.
An important object of the present invention is to provide a knife sharpening device which substantially overcomes the above-described problem in prior art knife-sharpening devices.
More specifically, it is an object of the present invention to provide a knife sharpening device having a platform for supporting a stone thereon, and a guide bar vertically adjustable with respect to the stone, wherein the spacing between the guide bar and the upper face of the stone may be accurately determined and adjusted.
The present invention in knife sharpening apparatus includes a platform on which a sharpening stone is supported, and a support assembly or assemblies mounted for shifting along a path substantially normal to the plane of the platform. A guide bar mounted on the assembly, and extending substantially parallel to the face of the stone, is shiftable, along with the assembly, to produce a preselected spacing between the bar and the stone. Further, it is shiftable independently, relative to the assembly, to produce a desired spacing between the bar and the stone--such being measured relative to the "preselected spacing". The latter spacing is determined by a scale of markings carried on the assembly. With the knife sharpening apparatus so set, a knife blade placed with its working edge against the face of the stone and its opposite edge against the bar, is held at an accurately determined preselected angle.
These and other objects and advantages of the present invention will become more fully apparent when read in connection with the following detailed description of a preferred embodiment of the invention and the accompanying drawings.